1. Field of the Invention
The present invention relates to a compound which exhibits .beta.-adrenergic blocking activity. More particularly, the present invention relates to a pharmaceutically active compound related to the known .beta.-receptor blocking agent, propranolol.
2. Description of the Prior Art
Numerous compounds are known which exhibit .beta.-receptor blocking activity and therefore are useful in the treatment of heart and vascular dieseases such as angina pectoris, hypertension, vasoregulatoric neurasteni and some forms of arrythmia. For example, U.S. Pat. Nos. 4,036,988 and 4,039,685 show 1-phenoxy-2-hydroxy-3,5-butylamino propane derivatives which exhibit bradycardia and block isoproterenol activity. U.S. Pat. No. 3,998,790 shows a series of para-substituted phenoxy-hydroxy-propylamines which are therapeutically effective by their ability to block the .beta.-receptors of heart tissue. U.S. Pat. Nos. 3,337,628 and 3,432,545 show a number of propanolamine compounds which exhibit a .beta.-adrenergic blocking activity of which some derivatives contain a 1-naphthoxy substituent and the primary amino group is substituted by one or two alkyl or aralkyl radicals. An important conventional compound which contains a 1-naphthoxy substituent is propranolol which is a strong .beta.-adrenergic blocking agent. However, a disadvantage of propranolol is that it does not exhibit the degree of longevity of binding to .beta.-adrenergic receptors in mammalian cells that is desirable for .beta.-adrenergic blocking agents. Another disadvantage of propranolol is that patients who are taken off of propranolol suddenly or who abruptly stop taking the drug against medical advice may precipitate severe angina or myocardial infarction. Moreover, propranolol must be administered several times a day which is a factor in poor patient compliance in taking the drug. Still further, because of the frequency which propranolol must be taken, there is a concommitant increased risk of medication error.